Mertz Glacier (67°30′S 144°45′E / 67.500°S 144.750°E) is a heavily crevassed glacier in George V Coast of East Antarctica. It is the source of a glacial prominence that historically has extended northward into the Southern Ocean, the Mertz Glacial Tongue. It is named in honor of the Swiss explorer Xavier Mertz.
The Mertz-Ninnis Valley (67°25′S 146°0′E / 67.417°S 146.000°E) is an undersea valley named in association with the Mertz Glacier and the Ninnis Glacier.